Liquid metering apparatus for photographic developing device

ABSTRACT

Liquid metering apparatus for removing a predetermined amount of processing liquid from a reservoir in which the liquid level may vary, and feeding the removed liquid through a conduit to a developing chamber. The metering apparatus includes a cyclically immersed dipper having a chamber therein of a configuration enabling the separation and transfer of a precise amount of liquid from the reservoir even if the level of liquid in the reservoir varies.

United States Patent [1 1 Kitch LIQUID METERING APPARATUS FORPHOTOGRAPHIC DEVELOPING DEVICE Inventor: Paul E. Kitch, WestSpringfield,

Mass.

Assignee: The Plastic Coating Corporation,

South Hadley, Mass.

Filed: Dec. 18, 1969 Appl. No.: 886,132

us. Cl. ..9s/94 G, 95/89 G rm. Cl. ..G03d 3/12 Field of Search ...95/s9R, 89 G, 94 0-, 222/356, 222/367 Rem-mes Cited UNITED STATES PATENTS3/1921 Mott.-. ..222/56 [111 3,753,394 [451 Aug.2l, 1973 1,929,69310/1933 Jones et al. ..222/$7 2,302,277 11/1942 Von Meister ..95/89 G2,828,049 3/1958 Midgley ..222/4 2,989,912 6/ 1961 Brundage ..95/89 GPrimary ExaminerSamuel S. Matthews Assistant Examiner-Fred L. BraunAttorney-William J Foley, Martin L. Faigus, John W. Kane, Jr. and JohnA. Weygandt ABSTRACT 7Claims,2DrawingFlgures LIQUID METERING APPARATUSFOR PI-IOTOGRAPHIC DEVELOPING DEVICE BACKGROUND OF THE INVENTION 1.Field of the Invention This invention relates to liquid meteringapparatus and, more particularly, to apparatus for removingpredetermined amounts of liquid from a reservoir in which the liquidlevel may vary.

2. Brief Description of the Prior Art In the past, apparatus employing adipper to transfer liquid from a reservoir to a remote point has beenutilized. However, in instances where such apparatus was employed for ametering function, that is, where a mea sured amount of liquid was to beremoved from the reservoir by the dipper, it has always been necessaryto maintain the level of liquid in the reservoir at a given height inorder to insure that the amount of liquid picked up by the dipper wouldbe consistent. Otherwise, the dipper had to be pivotably mounted as ongimbals and provision made for removing the liquid from the dipper. Thisrequired introducing additional mechanical elements into the meteringapparatus which it would be desirable to eliminate. However, previousattempts to eliminate such mechanical elements without regulating thelevel of liquid in the reservoir from which liquid was being meteredhave not been entirely satisfactory.

In many instances, the above limitations on metering devices have causedspecial problems because of the types of liquids being metered. Forexample, where effervescent liquids are to be metered from a reservoirand delivered to a remote point, pumps have often been utilized.However, pumps tend to vapor lock due to the high vapor pressures of theliquids involved. Obviously, this causes severe problemswhere continuityof supply of the effervescent liquids is an extremely important feature,such as in a continuous process for developing photographic materials instrip form.

It is the chief object and advantage of the present invention to providea new and improved liquid metering apparatus for removing apredetermined amount of liquid from a reservoir in which the liquidlevel may vary.

SUMMARY OF THE INVENTION The invention is a liquid metering apparatusfor removing a predetermined amount of liquid from a reservoir in whichthe liquid level may vary. The apparatus includes a novel dipper adaptedto transport liquid, which dipper has a cylindrical chamber thereindisposed with its cylindrical axis substantially horizontal and has atleast one axially disposed circular opening into the cylindricalchamber. The diameter of the opening is smaller than the diameter of thecylindrical chamber so as to form an annular liquid-retaining groove.Dipper transport means are provided for cyclically immersing the dipperin the reservoir. Conduit means connect the dipper to a remote positionoutside of the reservoir. The conduit means are adapted to receiveliquid from the dipper when the dipper is disposed above the surface ofthe liquid in the reservoir. The above apparatus accomplishes theremoval of a predetermined amount ofliquid from the reservoir by thedipper when the dipper is withdrawn from the liquid in the reservoirafter immersion therein. In the a diazotype film to render visible animage thereon.

This combination includes a development chamber and means to feed astrip of diazotype film, having a developable image thereon, into andout of the development chamber. Means are provided for maintaining aprescribed minimum vapor pressure of ammonia in the development chamber,which means include liquid evaporator means including heating meansdisposed in the development chamber, and liquid supply means adapted tofeed metered amounts of aqueous ammonia to the liquid evaporator means.The liquid supply means comprise the liquid metering apparatus mentionedabove.

The liquid metering apparatus of the invention including the noveldipper provide a means for removing predetermined amounts of liquid froma reservoir even when the liquid level in the reservoir varies. Its usein combination with other elements of equipment for developing adiazotype film results in greater reliability and continuity ofdevelopment than has been the case in the past. In particular, theapparatus is particularly useful where effervescent liquids are to bemetered from a source.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional sideelevation view of apparatus of the present invention illustrating theliquid metering apparatus in combination with other elements of theequipment for developing a diazotype image; and

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, ahousing 10 defines adevelopment chamber 11 in which diazotype film isdeveloped. The film to be developed has received a light image on itsphotosensitive surface prior to entering the chamber 11, which forms alatent image to be developed. The latent image is to be developed withinthe chamber 11 by subjecting it to ammonia under certain conditions oftime and temperature well known to those skilled in the art whereuponthe image will be rendered visible. The film is fed into the chamber 11through a slit opening 12 and is festooned over and suspended between aplurality of guide rollers 13 to expose its surface to the atmospherewithin the development chamber 11. It is then drawn from the chamber 11through a further slit opening 14 to be processed and wound. Rollers 13are driven by motors 15 operating through shafts 16 penetrating the sidewall of the housing 10. Alternatively the film may be drawn through thehousing 10 by means (not shown) located outside of the housing 10 andthe rollers 13 may be the idler rollers.

Development of the image on the diazotype film depends in part upon thevapor pressure of ammonia which is maintained within the chamber 11.Thus, it is important to supplant the ammonia vapor which is lost moniaper unit time within the chamber 11. The

evaporated ammonia thus prevents the attenuation of the vapor pressureof the ammonia within the chamber below a minimum level.

A tray 17 is provided near the bottom of the housing for receivingaqueous ammonia from a source outside of the chamber 11. The tray 17provides a cavity 18 for holding the liquid to be evaporated to increasethe depleting vapor pressure. Heating means in the form of a resistanceelement 20 electrically connected to wires 21 and 22 leading to a sourceof electrical power (not shown), are embedded in the tray 17. Heat fromthe resistance element 20 is conducted to the liquid in the cavity ofthe tray.

The liquid metering apparatus of the invention is attached to the sidewall of the housing 10. The metering apparatus includes a housing 27having four side walls 23, a bottom wall 24, and a hinged top wall 25which permits access to the chamber 26 for inserting the aqueous ammoniaor other liquid to be metered. The housing 27 has a partition 28extending upwardly from the bottom wall 24 and connecting two opposedside walls so as to divide the lower portion of the chamber 26 withinthe housing 27 into two portions 30 and 31. The portion 30 of thechamber 26 is partially filled with a liquid 32 to be metered by theapparatus. The other portion 31 of the chamber 26 communicates with theinterior of the housing 10, that is, the chamber 11 by means of a pipe33 extending through an opening 34in a side wall of the housing 10 andthrough a side wall of the housing 27 at its lowermost point.

The apparatus includes a shaft 35 rotatably mounted in the side wall ofthe housing 27 and in the partition wall 28. The shaft 35 has a pulley36 on its through-extending end passing through'the side wall of thehousing 27. The pulley 36 is driven by a belt 37 connected to a motor38, the speed of which may be varied by means (not shown) and in amanner well known to those skilled in the art. An arm 40 connects to theshaft 35 and is moved through an orbital path about the shaft 35 as theshaft 35 rotates. The arm 40 carries a dipper 41 on its radiallyoutermost end which is adapted to move through the orbital pathindicated by arrows 42 during which it is immersed in the liquid 32contained in the portion 30 of the chamber 26.

The dipper 41 defines a cylindrical chamber 43 therein having ahorizontal cylindrical axis. The dipper 41 has an axially disposedcircular opening 44 through each of its end walls; the diameter of eachof the openings 44 being smaller than the diameter of the cylindricalchamber 43. In this manner, the dipper 41 defines an annular groove orspace which is capable of The arm 40 has a passageway 45 therethroughwhich connects with the annular space in the dipper 41 through anopening in the wall forming the inner cylindrical surface of the dipper41. The radially inward end of the arm 40 connects with a passageway 46extending from the end of the shaft 35 to the point where the arm 40connects to the shaft 35. The end of the shaft 35 is retaining apredetermined amount of liquid in a cylindrical segment thereofregardless of the location of the dipper along its orbital path.

The amount of liquid retained by the dipper 41 depends upon the diameterof the cylindrical chamber 43, the thickness of the chamber 43, and thediameter of the openings 44 since, upon submerging and withdrawing thedipper from a body of liquid, the excess liquid flows over the edges ofopenings 44 until only a predetermined cylindrical segment is leftfilled.

of larger diameter along the portion containing the passageway 46; Itwill thus be apparent that when the dipper 41 is disposed above thelevel of the liquid 32 in the reservoir and above the axis of the shaft35, liquid in the dipper 41 will flow from the annular space through thepassageway 45 in the arm 40 and through the passageway 46 in the shaft35. The passageway 46 in the shaft 35 is tapered radially outwardlytoward the end of the shaft 35 from the point where the passageway 45 inthe arm 40 interconnects with the passageway 46 in the shaft 35. Liquidfrom the arm 40 drains from the end of the shaft 35 into the portion 31of the chamber 26 which connects with the development chamber 11 throughthe pipe 33.

A pair of inclined guide plates 47 are arranged in the portion 31 ofchamber 26 between the partition 28 and a side wall 23 of housing 27.The guide plates channel liquid from passageway 46 toward the opening tothe pipe 33.

In operation of the embodiment shown, care should be taken to maintainthe level of liquid 32 in the portion 30 of the chamber 26 between thedotted line, indicated by reference numeral 48, and the dotted line,indicated by reference numeral 50. The lower dotted line 48 indicatesthe level at which liquid is able to flow into the annular space of thedipper 41 when it is disposed in the lowermost point in its orbitalpath. The upper dotted line 50 represents the level at which liquidcontained within the annular space begins to flow into the passageway 45in arm 40. Obviously, no further liquid should enter the annular spaceof the dipper 41 through the openings 44 at that point since this wouldbe additive to the predetermined amount of liquid to be fed.

The above description shows that the invention provides apparatus formetering liquid from a reservoir in which the liquid level may vary,which apparatus can be advantageously used in combination with otherelements of equipment for developing diazotype film. The apparatus isrelatively uncomplicated in construction and operation and eliminatesthe need for the sensitive control devices such as liquid level devicesused in the past. The apparatus is particularly useful in situationswhere an effervescent liquid is to be metered in that it avoids thevapor locking problems experienced with pumps.

From the above description of the invention, it will be apparent thatvarious modifications in the apparatus described in detail herein, maybe made within the scope of the invention. Therefore, the invention isnot to be limited to the specific details of the apparatus describedherein except as may be required by the following claims.

What is claimed is:

1. In combination in equipment for developing a diazotype film to rendervisible an image thereon,

a development chamber,

means to feed a strip of diazotype film having a developable imagethereon into and out of said development chamber,

means for maintaining a prescribed minimum vapor pressure of ammonia insaid development chamber, said means including liquid evaporator meansincluding heating means disposed in said development chamber, and liquidsupply means adapted to feed metered amounts of aqueous ammonia to saidliquid evaporator, said liquid supply means comprising a reservoircontaining aqueous ammonia,

a dipper adapted to transport aqueous ammonia, said dipper having acylindrical chamber therein disposed with its cylindrical axissubstantially horizontal, and having at least one axially disposedcircular opening into said cylindrical chamber, the diameter of saidopening being smaller than the diameter of said cylindrical chamber,

dipper transport means for cyclically immersing said dipper in theaqueous ammonia in said reservoir, and

conduit means connecting said dipper to the liquid evaporator meansdisposed in said development chamber and adapted to receive aqueousammonia from said dipper when said dipper is disposed above the surfaceof aqueous ammonia in said reservoir, whereby a predetermined amount ofaqueous ammonia is removed from said reservoir by said dipper when saiddipper is withdrawn from the aqueous ammonia in said reservoir afterimmersion therein.

2. In equipment for developing a diazotype film to render visible animage thereon, the combination according to claim 1, wherein said dipperhas two axially disposed circular openings into said cylindricalchamber, said openings being disposed at the respective ends of saidcylindrical chamber.

3. In equipment for developing a diazotype film to render visible animage thereon, the combination according to claim 1, wherein said dippertransport means include a rotatably mounted shaft, a motor operablyconnected to said shaft, and an arm depending radially outward from saidshaft and carrying said dipper on its outer end whereby, upon rotationof said shaft by said motor, said arm carries said dipper through anorbital path so that upon each revolution, said dipper is immersed inand withdrawn from the liquid in said reservoir.

4. In equipment for developing a diazotype film to render visible animage thereon, the combination according to claim 3, wherein said armhas an elongate passageway therethrough, one endof which communicateswith said cylindrical chamber, and wherein said shaft has a coaxialpassageway extending from one end thereof and communicating with thepassageway in said arm.

5. In equipment for developing a diazotype film to render visible animage thereon, the combination according to claim 4, wherein said dipperdefines an annular chamber for retaining a predetermined amount of fluidin a cylindrical segmentthereof regardless of the location of saiddipper along its orbital path.

6. In equipment for developing a diazotype film to renger visible an ige thereon, the combination accor ing to 0 arm 5, w erein the passagewayin said arm communicates with said annular chamber through an opening inthe cylindrical wall defining said annular chamber, the outer end ofsaid arm terminating at said cylindrical wall.

7. In equipment for developing a diazotype film to render visible animage thereon, the combination according to claim 6, wherein saidcoaxial passageway in said shaft tapers outwardly toward the end of saidshaft from the point where the elongate-passageway in said arminterconnects with the passageway in said shaft.

1. In combination in equipment for developing a diazotype film to rendervisible an image thereon, a development chamber, means to feed a stripof diazotype film having a developable image thereon into and out ofsaid development chamber, means for maintaining a prescribed minimumvapor pressure of ammonia in said development chamber, said meansincluding liquid evaporator means including heating means disposed insaid development chamber, and liquid supply means adapted to feedmetered amounts of aqueous ammonia to said liquid evaporator, saidliquid supply means comprising a reservoir containing aqueous ammonia, adipper adapted to transport aqueous ammonia, said dipper having acylindrical chamber therein disposed with its cylindrical axissubstantially horizontal, and having at least one axially disposedcircular opening into said cylindrical chamber, the diameter of saidopening being smaller than the diameter of said cylindrical chamber,dipper transport means for cyclically immersing said dipper in theaqueous ammonia in said reservoir, and conduit means connecting saiddipper to the liquid evaporator means disposed in said developmentchamber and adapted to receive aqueous ammonia from said dipper whensaid dipper is disposed above the surface of aqueous ammonia in saidreservoir, whereby a predetermined amount of aqueous ammonia is removedfrom said reservoir by said dipper when said dipper is withdrawn fromthe aqueous ammonia in said reservoir after immersion therein.
 2. Inequipment for developing a diazotype film to render visible an imagethereon, the combination according to claim 1, wherein said dipper hastwo axially disposed circular openings into said cylindrical chamber,said openings being disposed at the respective ends of said cylindricalchamber.
 3. In equipment for developing a diazotype film to rendervisible an image thereon, the combination according to claim 1, whereinsaid dipper transport means include a rotatably mounted shaft, a motoroperably connected to said shaft, and an arm depending radially outwardfrom said shaft and carrying said dipper on its outer end whereby, uponrotation of said shaft by said motor, said arm Carries said dipperthrough an orbital path so that upon each revolution, said dipper isimmersed in and withdrawn from the liquid in said reservoir.
 4. Inequipment for developing a diazotype film to render visible an imagethereon, the combination according to claim 3, wherein said arm has anelongate passageway therethrough, one end of which communicates withsaid cylindrical chamber, and wherein said shaft has a coaxialpassageway extending from one end thereof and communicating with thepassageway in said arm.
 5. In equipment for developing a diazotype filmto render visible an image thereon, the combination according to claim4, wherein said dipper defines an annular chamber for retaining apredetermined amount of fluid in a cylindrical segment thereofregardless of the location of said dipper along its orbital path.
 6. Inequipment for developing a diazotype film to render visible an imagethereon, the combination according to claim 5, wherein the passageway insaid arm communicates with said annular chamber through an opening inthe cylindrical wall defining said annular chamber, the outer end ofsaid arm terminating at said cylindrical wall.
 7. In equipment fordeveloping a diazotype film to render visible an image thereon, thecombination according to claim 6, wherein said coaxial passageway insaid shaft tapers outwardly toward the end of said shaft from the pointwhere the elongate passageway in said arm interconnects with thepassageway in said shaft.